ocp认证052考题解析:1Z0-V8.02-第65题
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65. Which two statements are true about checkpointing? (Choose two.)
A.The checkpoint frequency decreases with the smaller redo log file size.
B.It ensures that all committed data is written to the data files during normal shutdown.
C.The frequent full checkpoint in a database can cause the overall degradation of the database
performance.
D.It prompts the Checkpoint (CKPT) process to write data to the data files and redo information to the
online redo log files.
Answer: BC
答案解析:
A.当重做日志文件太小的情况下,会频繁的切换日志,检查点信息写入数据文件的频率会增加而不是减少。A错。
B.在正常关库,会生成完全检查点,CKPT会让DBWn进程将所有已经提交的都写进数据文件,B对。
C.频繁的发生检查点会增加I/O的读写次数,造成数据库性能的下降,故C对。
D.CKPT是将重做信息写进重做日志里,DBWn是将数据写进数据文件,而不是CKPT.D错。